RegionInfo.h revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f
1//===- RegionInfo.h - SESE region analysis ----------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// Calculate a program structure tree built out of single entry single exit 11// regions. 12// The basic ideas are taken from "The Program Structure Tree - Richard Johnson, 13// David Pearson, Keshav Pingali - 1994", however enriched with ideas from "The 14// Refined Process Structure Tree - Jussi Vanhatalo, Hagen Voelyer, Jana 15// Koehler - 2009". 16// The algorithm to calculate these data structures however is completely 17// different, as it takes advantage of existing information already available 18// in (Post)dominace tree and dominance frontier passes. This leads to a simpler 19// and in practice hopefully better performing algorithm. The runtime of the 20// algorithms described in the papers above are both linear in graph size, 21// O(V+E), whereas this algorithm is not, as the dominance frontier information 22// itself is not, but in practice runtime seems to be in the order of magnitude 23// of dominance tree calculation. 24// 25//===----------------------------------------------------------------------===// 26 27#ifndef LLVM_ANALYSIS_REGIONINFO_H 28#define LLVM_ANALYSIS_REGIONINFO_H 29 30#include "llvm/ADT/PointerIntPair.h" 31#include "llvm/ADT/iterator_range.h" 32#include "llvm/Analysis/DominanceFrontier.h" 33#include "llvm/Analysis/PostDominators.h" 34#include "llvm/Support/Allocator.h" 35#include <map> 36#include <memory> 37 38namespace llvm { 39 40class Region; 41class RegionInfo; 42class raw_ostream; 43class Loop; 44class LoopInfo; 45 46/// @brief Marker class to iterate over the elements of a Region in flat mode. 47/// 48/// The class is used to either iterate in Flat mode or by not using it to not 49/// iterate in Flat mode. During a Flat mode iteration all Regions are entered 50/// and the iteration returns every BasicBlock. If the Flat mode is not 51/// selected for SubRegions just one RegionNode containing the subregion is 52/// returned. 53template <class GraphType> 54class FlatIt {}; 55 56/// @brief A RegionNode represents a subregion or a BasicBlock that is part of a 57/// Region. 58class RegionNode { 59 RegionNode(const RegionNode &) LLVM_DELETED_FUNCTION; 60 const RegionNode &operator=(const RegionNode &) LLVM_DELETED_FUNCTION; 61 62protected: 63 /// This is the entry basic block that starts this region node. If this is a 64 /// BasicBlock RegionNode, then entry is just the basic block, that this 65 /// RegionNode represents. Otherwise it is the entry of this (Sub)RegionNode. 66 /// 67 /// In the BBtoRegionNode map of the parent of this node, BB will always map 68 /// to this node no matter which kind of node this one is. 69 /// 70 /// The node can hold either a Region or a BasicBlock. 71 /// Use one bit to save, if this RegionNode is a subregion or BasicBlock 72 /// RegionNode. 73 PointerIntPair<BasicBlock*, 1, bool> entry; 74 75 /// @brief The parent Region of this RegionNode. 76 /// @see getParent() 77 Region* parent; 78 79public: 80 /// @brief Create a RegionNode. 81 /// 82 /// @param Parent The parent of this RegionNode. 83 /// @param Entry The entry BasicBlock of the RegionNode. If this 84 /// RegionNode represents a BasicBlock, this is the 85 /// BasicBlock itself. If it represents a subregion, this 86 /// is the entry BasicBlock of the subregion. 87 /// @param isSubRegion If this RegionNode represents a SubRegion. 88 inline RegionNode(Region* Parent, BasicBlock* Entry, bool isSubRegion = 0) 89 : entry(Entry, isSubRegion), parent(Parent) {} 90 91 /// @brief Get the parent Region of this RegionNode. 92 /// 93 /// The parent Region is the Region this RegionNode belongs to. If for 94 /// example a BasicBlock is element of two Regions, there exist two 95 /// RegionNodes for this BasicBlock. Each with the getParent() function 96 /// pointing to the Region this RegionNode belongs to. 97 /// 98 /// @return Get the parent Region of this RegionNode. 99 inline Region* getParent() const { return parent; } 100 101 /// @brief Get the entry BasicBlock of this RegionNode. 102 /// 103 /// If this RegionNode represents a BasicBlock this is just the BasicBlock 104 /// itself, otherwise we return the entry BasicBlock of the Subregion 105 /// 106 /// @return The entry BasicBlock of this RegionNode. 107 inline BasicBlock* getEntry() const { return entry.getPointer(); } 108 109 /// @brief Get the content of this RegionNode. 110 /// 111 /// This can be either a BasicBlock or a subregion. Before calling getNodeAs() 112 /// check the type of the content with the isSubRegion() function call. 113 /// 114 /// @return The content of this RegionNode. 115 template<class T> 116 inline T* getNodeAs() const; 117 118 /// @brief Is this RegionNode a subregion? 119 /// 120 /// @return True if it contains a subregion. False if it contains a 121 /// BasicBlock. 122 inline bool isSubRegion() const { 123 return entry.getInt(); 124 } 125}; 126 127/// Print a RegionNode. 128inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node); 129 130template<> 131inline BasicBlock* RegionNode::getNodeAs<BasicBlock>() const { 132 assert(!isSubRegion() && "This is not a BasicBlock RegionNode!"); 133 return getEntry(); 134} 135 136template<> 137inline Region* RegionNode::getNodeAs<Region>() const { 138 assert(isSubRegion() && "This is not a subregion RegionNode!"); 139 return reinterpret_cast<Region*>(const_cast<RegionNode*>(this)); 140} 141 142//===----------------------------------------------------------------------===// 143/// @brief A single entry single exit Region. 144/// 145/// A Region is a connected subgraph of a control flow graph that has exactly 146/// two connections to the remaining graph. It can be used to analyze or 147/// optimize parts of the control flow graph. 148/// 149/// A <em> simple Region </em> is connected to the remaining graph by just two 150/// edges. One edge entering the Region and another one leaving the Region. 151/// 152/// An <em> extended Region </em> (or just Region) is a subgraph that can be 153/// transform into a simple Region. The transformation is done by adding 154/// BasicBlocks that merge several entry or exit edges so that after the merge 155/// just one entry and one exit edge exists. 156/// 157/// The \e Entry of a Region is the first BasicBlock that is passed after 158/// entering the Region. It is an element of the Region. The entry BasicBlock 159/// dominates all BasicBlocks in the Region. 160/// 161/// The \e Exit of a Region is the first BasicBlock that is passed after 162/// leaving the Region. It is not an element of the Region. The exit BasicBlock, 163/// postdominates all BasicBlocks in the Region. 164/// 165/// A <em> canonical Region </em> cannot be constructed by combining smaller 166/// Regions. 167/// 168/// Region A is the \e parent of Region B, if B is completely contained in A. 169/// 170/// Two canonical Regions either do not intersect at all or one is 171/// the parent of the other. 172/// 173/// The <em> Program Structure Tree</em> is a graph (V, E) where V is the set of 174/// Regions in the control flow graph and E is the \e parent relation of these 175/// Regions. 176/// 177/// Example: 178/// 179/// \verbatim 180/// A simple control flow graph, that contains two regions. 181/// 182/// 1 183/// / | 184/// 2 | 185/// / \ 3 186/// 4 5 | 187/// | | | 188/// 6 7 8 189/// \ | / 190/// \ |/ Region A: 1 -> 9 {1,2,3,4,5,6,7,8} 191/// 9 Region B: 2 -> 9 {2,4,5,6,7} 192/// \endverbatim 193/// 194/// You can obtain more examples by either calling 195/// 196/// <tt> "opt -regions -analyze anyprogram.ll" </tt> 197/// or 198/// <tt> "opt -view-regions-only anyprogram.ll" </tt> 199/// 200/// on any LLVM file you are interested in. 201/// 202/// The first call returns a textual representation of the program structure 203/// tree, the second one creates a graphical representation using graphviz. 204class Region : public RegionNode { 205 friend class RegionInfo; 206 Region(const Region &) LLVM_DELETED_FUNCTION; 207 const Region &operator=(const Region &) LLVM_DELETED_FUNCTION; 208 209 // Information necessary to manage this Region. 210 RegionInfo* RI; 211 DominatorTree *DT; 212 213 // The exit BasicBlock of this region. 214 // (The entry BasicBlock is part of RegionNode) 215 BasicBlock *exit; 216 217 typedef std::vector<std::unique_ptr<Region>> RegionSet; 218 219 // The subregions of this region. 220 RegionSet children; 221 222 typedef std::map<BasicBlock*, RegionNode*> BBNodeMapT; 223 224 // Save the BasicBlock RegionNodes that are element of this Region. 225 mutable BBNodeMapT BBNodeMap; 226 227 /// verifyBBInRegion - Check if a BB is in this Region. This check also works 228 /// if the region is incorrectly built. (EXPENSIVE!) 229 void verifyBBInRegion(BasicBlock* BB) const; 230 231 /// verifyWalk - Walk over all the BBs of the region starting from BB and 232 /// verify that all reachable basic blocks are elements of the region. 233 /// (EXPENSIVE!) 234 void verifyWalk(BasicBlock* BB, std::set<BasicBlock*>* visitedBB) const; 235 236 /// verifyRegionNest - Verify if the region and its children are valid 237 /// regions (EXPENSIVE!) 238 void verifyRegionNest() const; 239 240public: 241 /// @brief Create a new region. 242 /// 243 /// @param Entry The entry basic block of the region. 244 /// @param Exit The exit basic block of the region. 245 /// @param RI The region info object that is managing this region. 246 /// @param DT The dominator tree of the current function. 247 /// @param Parent The surrounding region or NULL if this is a top level 248 /// region. 249 Region(BasicBlock *Entry, BasicBlock *Exit, RegionInfo* RI, 250 DominatorTree *DT, Region *Parent = nullptr); 251 252 /// Delete the Region and all its subregions. 253 ~Region(); 254 255 /// @brief Get the entry BasicBlock of the Region. 256 /// @return The entry BasicBlock of the region. 257 BasicBlock *getEntry() const { return RegionNode::getEntry(); } 258 259 /// @brief Replace the entry basic block of the region with the new basic 260 /// block. 261 /// 262 /// @param BB The new entry basic block of the region. 263 void replaceEntry(BasicBlock *BB); 264 265 /// @brief Replace the exit basic block of the region with the new basic 266 /// block. 267 /// 268 /// @param BB The new exit basic block of the region. 269 void replaceExit(BasicBlock *BB); 270 271 /// @brief Recursively replace the entry basic block of the region. 272 /// 273 /// This function replaces the entry basic block with a new basic block. It 274 /// also updates all child regions that have the same entry basic block as 275 /// this region. 276 /// 277 /// @param NewEntry The new entry basic block. 278 void replaceEntryRecursive(BasicBlock *NewEntry); 279 280 /// @brief Recursively replace the exit basic block of the region. 281 /// 282 /// This function replaces the exit basic block with a new basic block. It 283 /// also updates all child regions that have the same exit basic block as 284 /// this region. 285 /// 286 /// @param NewExit The new exit basic block. 287 void replaceExitRecursive(BasicBlock *NewExit); 288 289 /// @brief Get the exit BasicBlock of the Region. 290 /// @return The exit BasicBlock of the Region, NULL if this is the TopLevel 291 /// Region. 292 BasicBlock *getExit() const { return exit; } 293 294 /// @brief Get the parent of the Region. 295 /// @return The parent of the Region or NULL if this is a top level 296 /// Region. 297 Region *getParent() const { return RegionNode::getParent(); } 298 299 /// @brief Get the RegionNode representing the current Region. 300 /// @return The RegionNode representing the current Region. 301 RegionNode* getNode() const { 302 return const_cast<RegionNode*>(reinterpret_cast<const RegionNode*>(this)); 303 } 304 305 /// @brief Get the nesting level of this Region. 306 /// 307 /// An toplevel Region has depth 0. 308 /// 309 /// @return The depth of the region. 310 unsigned getDepth() const; 311 312 /// @brief Check if a Region is the TopLevel region. 313 /// 314 /// The toplevel region represents the whole function. 315 bool isTopLevelRegion() const { return exit == nullptr; } 316 317 /// @brief Return a new (non-canonical) region, that is obtained by joining 318 /// this region with its predecessors. 319 /// 320 /// @return A region also starting at getEntry(), but reaching to the next 321 /// basic block that forms with getEntry() a (non-canonical) region. 322 /// NULL if such a basic block does not exist. 323 Region *getExpandedRegion() const; 324 325 /// @brief Return the first block of this region's single entry edge, 326 /// if existing. 327 /// 328 /// @return The BasicBlock starting this region's single entry edge, 329 /// else NULL. 330 BasicBlock *getEnteringBlock() const; 331 332 /// @brief Return the first block of this region's single exit edge, 333 /// if existing. 334 /// 335 /// @return The BasicBlock starting this region's single exit edge, 336 /// else NULL. 337 BasicBlock *getExitingBlock() const; 338 339 /// @brief Is this a simple region? 340 /// 341 /// A region is simple if it has exactly one exit and one entry edge. 342 /// 343 /// @return True if the Region is simple. 344 bool isSimple() const; 345 346 /// @brief Returns the name of the Region. 347 /// @return The Name of the Region. 348 std::string getNameStr() const; 349 350 /// @brief Return the RegionInfo object, that belongs to this Region. 351 RegionInfo *getRegionInfo() const { 352 return RI; 353 } 354 355 /// PrintStyle - Print region in difference ways. 356 enum PrintStyle { PrintNone, PrintBB, PrintRN }; 357 358 /// @brief Print the region. 359 /// 360 /// @param OS The output stream the Region is printed to. 361 /// @param printTree Print also the tree of subregions. 362 /// @param level The indentation level used for printing. 363 void print(raw_ostream& OS, bool printTree = true, unsigned level = 0, 364 enum PrintStyle Style = PrintNone) const; 365 366 /// @brief Print the region to stderr. 367 void dump() const; 368 369 /// @brief Check if the region contains a BasicBlock. 370 /// 371 /// @param BB The BasicBlock that might be contained in this Region. 372 /// @return True if the block is contained in the region otherwise false. 373 bool contains(const BasicBlock *BB) const; 374 375 /// @brief Check if the region contains another region. 376 /// 377 /// @param SubRegion The region that might be contained in this Region. 378 /// @return True if SubRegion is contained in the region otherwise false. 379 bool contains(const Region *SubRegion) const { 380 // Toplevel Region. 381 if (!getExit()) 382 return true; 383 384 return contains(SubRegion->getEntry()) 385 && (contains(SubRegion->getExit()) || SubRegion->getExit() == getExit()); 386 } 387 388 /// @brief Check if the region contains an Instruction. 389 /// 390 /// @param Inst The Instruction that might be contained in this region. 391 /// @return True if the Instruction is contained in the region otherwise false. 392 bool contains(const Instruction *Inst) const { 393 return contains(Inst->getParent()); 394 } 395 396 /// @brief Check if the region contains a loop. 397 /// 398 /// @param L The loop that might be contained in this region. 399 /// @return True if the loop is contained in the region otherwise false. 400 /// In case a NULL pointer is passed to this function the result 401 /// is false, except for the region that describes the whole function. 402 /// In that case true is returned. 403 bool contains(const Loop *L) const; 404 405 /// @brief Get the outermost loop in the region that contains a loop. 406 /// 407 /// Find for a Loop L the outermost loop OuterL that is a parent loop of L 408 /// and is itself contained in the region. 409 /// 410 /// @param L The loop the lookup is started. 411 /// @return The outermost loop in the region, NULL if such a loop does not 412 /// exist or if the region describes the whole function. 413 Loop *outermostLoopInRegion(Loop *L) const; 414 415 /// @brief Get the outermost loop in the region that contains a basic block. 416 /// 417 /// Find for a basic block BB the outermost loop L that contains BB and is 418 /// itself contained in the region. 419 /// 420 /// @param LI A pointer to a LoopInfo analysis. 421 /// @param BB The basic block surrounded by the loop. 422 /// @return The outermost loop in the region, NULL if such a loop does not 423 /// exist or if the region describes the whole function. 424 Loop *outermostLoopInRegion(LoopInfo *LI, BasicBlock* BB) const; 425 426 /// @brief Get the subregion that starts at a BasicBlock 427 /// 428 /// @param BB The BasicBlock the subregion should start. 429 /// @return The Subregion if available, otherwise NULL. 430 Region* getSubRegionNode(BasicBlock *BB) const; 431 432 /// @brief Get the RegionNode for a BasicBlock 433 /// 434 /// @param BB The BasicBlock at which the RegionNode should start. 435 /// @return If available, the RegionNode that represents the subregion 436 /// starting at BB. If no subregion starts at BB, the RegionNode 437 /// representing BB. 438 RegionNode* getNode(BasicBlock *BB) const; 439 440 /// @brief Get the BasicBlock RegionNode for a BasicBlock 441 /// 442 /// @param BB The BasicBlock for which the RegionNode is requested. 443 /// @return The RegionNode representing the BB. 444 RegionNode* getBBNode(BasicBlock *BB) const; 445 446 /// @brief Add a new subregion to this Region. 447 /// 448 /// @param SubRegion The new subregion that will be added. 449 /// @param moveChildren Move the children of this region, that are also 450 /// contained in SubRegion into SubRegion. 451 void addSubRegion(Region *SubRegion, bool moveChildren = false); 452 453 /// @brief Remove a subregion from this Region. 454 /// 455 /// The subregion is not deleted, as it will probably be inserted into another 456 /// region. 457 /// @param SubRegion The SubRegion that will be removed. 458 Region *removeSubRegion(Region *SubRegion); 459 460 /// @brief Move all direct child nodes of this Region to another Region. 461 /// 462 /// @param To The Region the child nodes will be transferred to. 463 void transferChildrenTo(Region *To); 464 465 /// @brief Verify if the region is a correct region. 466 /// 467 /// Check if this is a correctly build Region. This is an expensive check, as 468 /// the complete CFG of the Region will be walked. 469 void verifyRegion() const; 470 471 /// @brief Clear the cache for BB RegionNodes. 472 /// 473 /// After calling this function the BasicBlock RegionNodes will be stored at 474 /// different memory locations. RegionNodes obtained before this function is 475 /// called are therefore not comparable to RegionNodes abtained afterwords. 476 void clearNodeCache(); 477 478 /// @name Subregion Iterators 479 /// 480 /// These iterators iterator over all subregions of this Region. 481 //@{ 482 typedef RegionSet::iterator iterator; 483 typedef RegionSet::const_iterator const_iterator; 484 485 iterator begin() { return children.begin(); } 486 iterator end() { return children.end(); } 487 488 const_iterator begin() const { return children.begin(); } 489 const_iterator end() const { return children.end(); } 490 //@} 491 492 /// @name BasicBlock Iterators 493 /// 494 /// These iterators iterate over all BasicBlocks that are contained in this 495 /// Region. The iterator also iterates over BasicBlocks that are elements of 496 /// a subregion of this Region. It is therefore called a flat iterator. 497 //@{ 498 template <bool IsConst> 499 class block_iterator_wrapper 500 : public df_iterator<typename std::conditional<IsConst, const BasicBlock, 501 BasicBlock>::type *> { 502 typedef df_iterator<typename std::conditional<IsConst, const BasicBlock, 503 BasicBlock>::type *> super; 504 505 public: 506 typedef block_iterator_wrapper<IsConst> Self; 507 typedef typename super::pointer pointer; 508 509 // Construct the begin iterator. 510 block_iterator_wrapper(pointer Entry, pointer Exit) : super(df_begin(Entry)) 511 { 512 // Mark the exit of the region as visited, so that the children of the 513 // exit and the exit itself, i.e. the block outside the region will never 514 // be visited. 515 super::Visited.insert(Exit); 516 } 517 518 // Construct the end iterator. 519 block_iterator_wrapper() : super(df_end<pointer>((BasicBlock *)nullptr)) {} 520 521 /*implicit*/ block_iterator_wrapper(super I) : super(I) {} 522 523 // FIXME: Even a const_iterator returns a non-const BasicBlock pointer. 524 // This was introduced for backwards compatibility, but should 525 // be removed as soon as all users are fixed. 526 BasicBlock *operator*() const { 527 return const_cast<BasicBlock*>(super::operator*()); 528 } 529 }; 530 531 typedef block_iterator_wrapper<false> block_iterator; 532 typedef block_iterator_wrapper<true> const_block_iterator; 533 534 block_iterator block_begin() { 535 return block_iterator(getEntry(), getExit()); 536 } 537 538 block_iterator block_end() { 539 return block_iterator(); 540 } 541 542 const_block_iterator block_begin() const { 543 return const_block_iterator(getEntry(), getExit()); 544 } 545 const_block_iterator block_end() const { 546 return const_block_iterator(); 547 } 548 549 typedef iterator_range<block_iterator> block_range; 550 typedef iterator_range<const_block_iterator> const_block_range; 551 552 /// @brief Returns a range view of the basic blocks in the region. 553 inline block_range blocks() { 554 return block_range(block_begin(), block_end()); 555 } 556 557 /// @brief Returns a range view of the basic blocks in the region. 558 /// 559 /// This is the 'const' version of the range view. 560 inline const_block_range blocks() const { 561 return const_block_range(block_begin(), block_end()); 562 } 563 //@} 564 565 /// @name Element Iterators 566 /// 567 /// These iterators iterate over all BasicBlock and subregion RegionNodes that 568 /// are direct children of this Region. It does not iterate over any 569 /// RegionNodes that are also element of a subregion of this Region. 570 //@{ 571 typedef df_iterator<RegionNode*, SmallPtrSet<RegionNode*, 8>, false, 572 GraphTraits<RegionNode*> > element_iterator; 573 574 typedef df_iterator<const RegionNode*, SmallPtrSet<const RegionNode*, 8>, 575 false, GraphTraits<const RegionNode*> > 576 const_element_iterator; 577 578 element_iterator element_begin(); 579 element_iterator element_end(); 580 581 const_element_iterator element_begin() const; 582 const_element_iterator element_end() const; 583 //@} 584}; 585 586//===----------------------------------------------------------------------===// 587/// @brief Analysis that detects all canonical Regions. 588/// 589/// The RegionInfo pass detects all canonical regions in a function. The Regions 590/// are connected using the parent relation. This builds a Program Structure 591/// Tree. 592class RegionInfo : public FunctionPass { 593 typedef DenseMap<BasicBlock*,BasicBlock*> BBtoBBMap; 594 typedef DenseMap<BasicBlock*, Region*> BBtoRegionMap; 595 typedef SmallPtrSet<Region*, 4> RegionSet; 596 597 RegionInfo(const RegionInfo &) LLVM_DELETED_FUNCTION; 598 const RegionInfo &operator=(const RegionInfo &) LLVM_DELETED_FUNCTION; 599 600 DominatorTree *DT; 601 PostDominatorTree *PDT; 602 DominanceFrontier *DF; 603 604 /// The top level region. 605 Region *TopLevelRegion; 606 607 /// Map every BB to the smallest region, that contains BB. 608 BBtoRegionMap BBtoRegion; 609 610 // isCommonDomFrontier - Returns true if BB is in the dominance frontier of 611 // entry, because it was inherited from exit. In the other case there is an 612 // edge going from entry to BB without passing exit. 613 bool isCommonDomFrontier(BasicBlock* BB, BasicBlock* entry, 614 BasicBlock* exit) const; 615 616 // isRegion - Check if entry and exit surround a valid region, based on 617 // dominance tree and dominance frontier. 618 bool isRegion(BasicBlock* entry, BasicBlock* exit) const; 619 620 // insertShortCut - Saves a shortcut pointing from entry to exit. 621 // This function may extend this shortcut if possible. 622 void insertShortCut(BasicBlock* entry, BasicBlock* exit, 623 BBtoBBMap* ShortCut) const; 624 625 // getNextPostDom - Returns the next BB that postdominates N, while skipping 626 // all post dominators that cannot finish a canonical region. 627 DomTreeNode *getNextPostDom(DomTreeNode* N, BBtoBBMap *ShortCut) const; 628 629 // isTrivialRegion - A region is trivial, if it contains only one BB. 630 bool isTrivialRegion(BasicBlock *entry, BasicBlock *exit) const; 631 632 // createRegion - Creates a single entry single exit region. 633 Region *createRegion(BasicBlock *entry, BasicBlock *exit); 634 635 // findRegionsWithEntry - Detect all regions starting with bb 'entry'. 636 void findRegionsWithEntry(BasicBlock *entry, BBtoBBMap *ShortCut); 637 638 // scanForRegions - Detects regions in F. 639 void scanForRegions(Function &F, BBtoBBMap *ShortCut); 640 641 // getTopMostParent - Get the top most parent with the same entry block. 642 Region *getTopMostParent(Region *region); 643 644 // buildRegionsTree - build the region hierarchy after all region detected. 645 void buildRegionsTree(DomTreeNode *N, Region *region); 646 647 // Calculate - detecte all regions in function and build the region tree. 648 void Calculate(Function& F); 649 650 void releaseMemory() override; 651 652 // updateStatistics - Update statistic about created regions. 653 void updateStatistics(Region *R); 654 655 // isSimple - Check if a region is a simple region with exactly one entry 656 // edge and exactly one exit edge. 657 bool isSimple(Region* R) const; 658 659public: 660 static char ID; 661 explicit RegionInfo(); 662 663 ~RegionInfo(); 664 665 /// @name FunctionPass interface 666 //@{ 667 bool runOnFunction(Function &F) override; 668 void getAnalysisUsage(AnalysisUsage &AU) const override; 669 void print(raw_ostream &OS, const Module *) const override; 670 void verifyAnalysis() const override; 671 //@} 672 673 /// @brief Get the smallest region that contains a BasicBlock. 674 /// 675 /// @param BB The basic block. 676 /// @return The smallest region, that contains BB or NULL, if there is no 677 /// region containing BB. 678 Region *getRegionFor(BasicBlock *BB) const; 679 680 /// @brief Set the smallest region that surrounds a basic block. 681 /// 682 /// @param BB The basic block surrounded by a region. 683 /// @param R The smallest region that surrounds BB. 684 void setRegionFor(BasicBlock *BB, Region *R); 685 686 /// @brief A shortcut for getRegionFor(). 687 /// 688 /// @param BB The basic block. 689 /// @return The smallest region, that contains BB or NULL, if there is no 690 /// region containing BB. 691 Region *operator[](BasicBlock *BB) const; 692 693 /// @brief Return the exit of the maximal refined region, that starts at a 694 /// BasicBlock. 695 /// 696 /// @param BB The BasicBlock the refined region starts. 697 BasicBlock *getMaxRegionExit(BasicBlock *BB) const; 698 699 /// @brief Find the smallest region that contains two regions. 700 /// 701 /// @param A The first region. 702 /// @param B The second region. 703 /// @return The smallest region containing A and B. 704 Region *getCommonRegion(Region* A, Region *B) const; 705 706 /// @brief Find the smallest region that contains two basic blocks. 707 /// 708 /// @param A The first basic block. 709 /// @param B The second basic block. 710 /// @return The smallest region that contains A and B. 711 Region* getCommonRegion(BasicBlock* A, BasicBlock *B) const { 712 return getCommonRegion(getRegionFor(A), getRegionFor(B)); 713 } 714 715 /// @brief Find the smallest region that contains a set of regions. 716 /// 717 /// @param Regions A vector of regions. 718 /// @return The smallest region that contains all regions in Regions. 719 Region* getCommonRegion(SmallVectorImpl<Region*> &Regions) const; 720 721 /// @brief Find the smallest region that contains a set of basic blocks. 722 /// 723 /// @param BBs A vector of basic blocks. 724 /// @return The smallest region that contains all basic blocks in BBS. 725 Region* getCommonRegion(SmallVectorImpl<BasicBlock*> &BBs) const; 726 727 Region *getTopLevelRegion() const { 728 return TopLevelRegion; 729 } 730 731 /// @brief Update RegionInfo after a basic block was split. 732 /// 733 /// @param NewBB The basic block that was created before OldBB. 734 /// @param OldBB The old basic block. 735 void splitBlock(BasicBlock* NewBB, BasicBlock *OldBB); 736 737 /// @brief Clear the Node Cache for all Regions. 738 /// 739 /// @see Region::clearNodeCache() 740 void clearNodeCache() { 741 if (TopLevelRegion) 742 TopLevelRegion->clearNodeCache(); 743 } 744}; 745 746inline raw_ostream &operator<<(raw_ostream &OS, const RegionNode &Node) { 747 if (Node.isSubRegion()) 748 return OS << Node.getNodeAs<Region>()->getNameStr(); 749 else 750 return OS << Node.getNodeAs<BasicBlock>()->getName(); 751} 752} // End llvm namespace 753#endif 754 755